Run an Experiment on FrameworkController¶

NNI supports running experiment using FrameworkController, called frameworkcontroller mode. FrameworkController is built to orchestrate all kinds of applications on Kubernetes, you don’t need to install Kubeflow for specific deep learning framework like tf-operator or pytorch-operator. Now you can use FrameworkController as the training service to run NNI experiment.

Prerequisite for on-premises Kubernetes Service¶

A Kubernetes cluster using Kubernetes 1.8 or later. Follow this guideline to set up Kubernetes
Prepare a kubeconfig file, which will be used by NNI to interact with your Kubernetes API server. By default, NNI manager will use $(HOME)/.kube/config as kubeconfig file’s path. You can also specify other kubeconfig files by setting the**KUBECONFIG** environment variable. Refer this guideline to learn more about kubeconfig.
If your NNI trial job needs GPU resource, you should follow this guideline to configure Nvidia device plugin for Kubernetes.
Prepare a NFS server and export a general purpose mount (we recommend to map your NFS server path in root_squash option, otherwise permission issue may raise when NNI copies files to NFS. Refer this page to learn what root_squash option is), or Azure File Storage.
Install NFS client on the machine where you install NNI and run nnictl to create experiment. Run this command to install NFSv4 client:

apt-get install nfs-common

Install NNI, follow the install guide here.

Prerequisite for Azure Kubernetes Service¶

NNI support Kubeflow based on Azure Kubernetes Service, follow the guideline to set up Azure Kubernetes Service.
Install Azure CLI and kubectl. Use az login to set azure account, and connect kubectl client to AKS, refer this guideline.
Follow the guideline to create azure file storage account. If you use Azure Kubernetes Service, NNI need Azure Storage Service to store code files and the output files.
To access Azure storage service, NNI need the access key of the storage account, and NNI uses Azure Key Vault Service to protect your private key. Set up Azure Key Vault Service, add a secret to Key Vault to store the access key of Azure storage account. Follow this guideline to store the access key.

Prerequisite for PVC storage mode¶

In order to use persistent volume claims instead of NFS or Azure storage, related storage must be created manually, in the namespace your trials will run later. This restriction is due to the fact, that persistent volume claims are hard to recycle and thus can quickly mess with a cluster’s storage management. Persistent volume claims can be created by e.g. using kubectl. Please refer to the official Kubernetes documentation for further information.

Setup FrameworkController¶

Follow the guideline to set up FrameworkController in the Kubernetes cluster, NNI supports FrameworkController by the stateful set mode. If your cluster enforces authorization, you need to create a service account with granted permission for FrameworkController, and then pass the name of the FrameworkController service account to the NNI Experiment Config. refer

Design¶

Please refer the design of Kubeflow training service, FrameworkController training service pipeline is similar.

Example¶

The FrameworkController config file format is:

authorName: default
experimentName: example_mnist
trialConcurrency: 1
maxExecDuration: 10h
maxTrialNum: 100
#choice: local, remote, pai, kubeflow, frameworkcontroller
trainingServicePlatform: frameworkcontroller
searchSpacePath: ~/nni/examples/trials/mnist-tfv1/search_space.json
#choice: true, false
useAnnotation: false
tuner:
  #choice: TPE, Random, Anneal, Evolution
  builtinTunerName: TPE
  classArgs:
    #choice: maximize, minimize
    optimize_mode: maximize
assessor:
  builtinAssessorName: Medianstop
  classArgs:
    optimize_mode: maximize
trial:
  codeDir: ~/nni/examples/trials/mnist-tfv1
  taskRoles:
    - name: worker
      taskNum: 1
      command: python3 mnist.py
      gpuNum: 1
      cpuNum: 1
      memoryMB: 8192
      image: msranni/nni:latest
      frameworkAttemptCompletionPolicy:
        minFailedTaskCount: 1
        minSucceededTaskCount: 1
frameworkcontrollerConfig:
  storage: nfs
  nfs:
    server: {your_nfs_server}
    path: {your_nfs_server_exported_path}

If you use Azure Kubernetes Service, you should set frameworkcontrollerConfig in your config YAML file as follows:

frameworkcontrollerConfig:
  storage: azureStorage
  serviceAccountName: {your_frameworkcontroller_service_account_name}
  keyVault:
    vaultName: {your_vault_name}
    name: {your_secert_name}
  azureStorage:
    accountName: {your_storage_account_name}
    azureShare: {your_azure_share_name}

Note: You should explicitly set trainingServicePlatform: frameworkcontroller in NNI config YAML file if you want to start experiment in frameworkcontrollerConfig mode.

The trial’s config format for NNI frameworkcontroller mode is a simple version of FrameworkController’s official config, you could refer the Tensorflow example of FrameworkController for deep understanding.

Trial configuration in frameworkcontroller mode have the following configuration keys:

taskRoles: you could set multiple task roles in config file, and each task role is a basic unit to process in Kubernetes cluster.
- name: the name of task role specified, like “worker”, “ps”, “master”.
- taskNum: the replica number of the task role.
- command: the users’ command to be used in the container.
- gpuNum: the number of gpu device used in container.
- cpuNum: the number of cpu device used in container.
- memoryMB: the memory limitaion to be specified in container.
- image: the docker image used to create pod and run the program.
- frameworkAttemptCompletionPolicy: the policy to run framework, please refer the user-manual to get the specific information. Users could use the policy to control the pod, for example, if ps does not stop, only worker stops, The completion policy could helps stop ps.

NNI also offers the possibility to include a customized frameworkcontroller template similar to the aforementioned tensorflow example. A valid configuration the may look like:

experimentName: example_mnist_pytorch
trialConcurrency: 1
maxExecDuration: 1h
maxTrialNum: 2
logLevel: trace
trainingServicePlatform: frameworkcontroller
searchSpacePath: search_space.json
tuner:
  builtinTunerName: TPE
  classArgs:
    optimize_mode: maximize
assessor:
  builtinAssessorName: Medianstop
  classArgs:
    optimize_mode: maximize
trial:
  codeDir: .
frameworkcontrollerConfig:
  configPath: fc_template.yml
  storage: pvc
  namespace: twin-pipelines
  pvc:
    path: /mnt/data

Note that in this example a persistent volume claim has been used, that must be created manually in the specified namespace beforehand. Stick to the mnist-pytorch example (:githublink: examples/trials/mnist-pytorch) for a more detailed config (:githublink: examples/trials/mnist-pytorch/config_frameworkcontroller_custom.yml) and frameworkcontroller template (:githublink: examples/trials/fc_template.yml).

How to run example¶

After you prepare a config file, you could run your experiment by nnictl. The way to start an experiment on FrameworkController is similar to Kubeflow, please refer the document for more information.

version check¶

NNI support version check feature in since version 0.6, refer